Naval warfare is combat in and on the sea, the ocean, or any other battlespace involving a major body of water such as a large lake or wide river. Mankind has fought battles on the sea for more than 3,000 years. Even in the interior of large landmasses, transportation before the advent of extensive railroads was largely dependent upon rivers, canals, and other navigable waterways.
The latter were crucial in the development of the modern world in Britain, the Low Countries and northern Germany, for they enabled the bulk movement of goods and raw materials without which the Industrial Revolution would not have occurred. Before 1800 war materials largely moved by river barge or sea vessels and needed a naval defence against enemies.